code: def test_multibox_prior_op():
      h = 561
      w = 728
      X = mx.nd.random.uniform(shape=(1, 3, h, w))
      Y = mx.contrib.nd.MultiBoxPrior(
          X, sizes=[0.75, 0.5, 0.25], ratios=[1, 2, 0.5]
      )
      assert_array_equal(Y.shape, np.array((1, 2042040, 4)))
      boxes = Y.reshape((h, w, 5, 4))
      assert_allclose(
          boxes.asnumpy()[250, 250, 0, :],
          np.array([0.055117, 0.071524, 0.63307, 0.821524]),
          atol=1e-5,
          rtol=1e-5,
      )
      # relax first ratio if user insists
      Y = mx.contrib.nd.MultiBoxPrior(
          X, sizes=[0.75, 0.5, 0.25], ratios=[20, 2, 0.5]
      )
      boxes = Y.reshape((h, w, 5, 4))
      assert_allclose(
          boxes.asnumpy()[250, 250, 0, :],
          np.array([-0.948249, 0.362671, 1.636436, 0.530377]),
          atol=1e-5,
          rtol=1e-5,
      )
  
file_path: mxnet/tests/python/unittest/test_contrib_operator.py
imports: from __future__ import print_function
  import numpy
  import mxnet
  import random
  import itertools
  from numpy.testing import assert_allclose, assert_array_equal
  from mxnet.test_utils import *
  from common import assert_raises_cudnn_not_satisfied, xfail_when_nonstandard_decimal_separator
  import unittest
label_desc: Use image node_id 6 for calling a global function with example usage: test_multibox_prior_op() without return types